21056410 has 8 divisors (see below), whose sum is σ = 37901556. Its totient is φ = 8422560.

The previous prime is 21056401. The next prime is 21056437. The reversal of 21056410 is 1465012.

It can be written as a sum of positive squares in 2 ways, for example, as 20241001 + 815409 = 4499^2 + 903^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1052811 + ... + 1052830.

Almost surely, 2^21056410 is an apocalyptic number.

21056410 is a deficient number, since it is larger than the sum of its proper divisors (16845146).

21056410 is a wasteful number, since it uses less digits than its factorization.

21056410 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2105648.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 21056410 is about 4588.7264028268. The cubic root of 21056410 is about 276.1392299698.

It can be divided in two parts, 2105 and 6410, that added together give a triangular number (8515 = T₁₃₀).

The spelling of 21056410 in words is "twenty-one million, fifty-six thousand, four hundred ten".